/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.editor;

import proguard.classfile.attribute.*;
import proguard.util.ArrayUtil;

/**
 * This class can add/remove bootstrap methods to/from a given bootstrap methods attribute. Bootstrap methods to be
 * added must have been filled out beforehand.
 *
 * @author Eric Lafortune
 */
public class BootstrapMethodsAttributeEditor {
    private BootstrapMethodsAttribute targetBootstrapMethodsAttribute;

    /**
     * Creates a new BootstrapMethodsAttributeEditor that will edit bootstrap methods in the given bootstrap methods
     * attribute.
     */
    public BootstrapMethodsAttributeEditor(BootstrapMethodsAttribute targetBootstrapMethodsAttribute) {
        this.targetBootstrapMethodsAttribute = targetBootstrapMethodsAttribute;
    }

    /**
     * Adds a given bootstrap method to the bootstrap methods attribute.
     * 
     * @return the index of the bootstrap method.
     */
    public int addBootstrapMethodInfo(BootstrapMethodInfo bootstrapMethodInfo) {
        targetBootstrapMethodsAttribute.bootstrapMethods =
            ArrayUtil.add(targetBootstrapMethodsAttribute.bootstrapMethods,
                targetBootstrapMethodsAttribute.u2bootstrapMethodsCount, bootstrapMethodInfo);

        return targetBootstrapMethodsAttribute.u2bootstrapMethodsCount++;
    }

    /**
     * Removes the given bootstrap method from the bootstrap method attribute.
     */
    public void removeBootstrapMethodInfo(BootstrapMethodInfo bootstrapMethodInfo) {
        ArrayUtil.remove(targetBootstrapMethodsAttribute.bootstrapMethods,
            targetBootstrapMethodsAttribute.u2bootstrapMethodsCount--,
            findBootstrapMethodInfoIndex(bootstrapMethodInfo));
    }

    /**
     * Finds the index of the given bootstrap method info in the target attribute.
     */
    private int findBootstrapMethodInfoIndex(BootstrapMethodInfo bootstrapMethodInfo) {
        int methodsCount = targetBootstrapMethodsAttribute.u2bootstrapMethodsCount;
        BootstrapMethodInfo[] methodInfos = targetBootstrapMethodsAttribute.bootstrapMethods;

        for (int index = 0; index < methodsCount; index++) {
            if (methodInfos[index].equals(bootstrapMethodInfo)) {
                return index;
            }
        }

        return methodsCount;
    }
}